Android imageView Zoom-in and Zoom-Out

Question

Hi i am new to Android application i want to Zoom-in and Zoom-out ImageView.I tried most of the sample but in all that image in the imageview is get Zoom-in and Zoom-out.I want to Zoom-in and Zoom-out ImageView.I want to increase imageview width and height while Zoom-in and reduce imageview width and height while Zoom-out.Can any one suggest me?

Answer 1

I made my own custom imageview with pinch to zoom. There is no limits/borders on Chirag Ravals code, so user can drag the image off the screen.

Here is the CustomImageView class:

    public class CustomImageVIew extends ImageView implements OnTouchListener {


    private Matrix matrix = new Matrix();
    private Matrix savedMatrix = new Matrix();

    static final int NONE = 0;
    static final int DRAG = 1;
    static final int ZOOM = 2;

    private int mode = NONE;

    private PointF mStartPoint = new PointF();
    private PointF mMiddlePoint = new PointF();
    private Point mBitmapMiddlePoint = new Point();

    private float oldDist = 1f;
    private float matrixValues[] = {0f, 0f, 0f, 0f, 0f, 0f, 0f, 0f, 0f};
    private float scale;
    private float oldEventX = 0;
    private float oldEventY = 0;
    private float oldStartPointX = 0;
    private float oldStartPointY = 0;
    private int mViewWidth = -1;
    private int mViewHeight = -1;
    private int mBitmapWidth = -1;
    private int mBitmapHeight = -1;
    private boolean mDraggable = false;


    public CustomImageVIew(Context context) {
        this(context, null, 0);
    }

    public CustomImageVIew(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CustomImageVIew(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        this.setOnTouchListener(this);
    }

    @Override
    public void onSizeChanged (int w, int h, int oldw, int oldh){
        super.onSizeChanged(w, h, oldw, oldh);
        mViewWidth = w;
        mViewHeight = h;
    }

    public void setBitmap(Bitmap bitmap){
        if(bitmap != null){
            setImageBitmap(bitmap);

            mBitmapWidth = bitmap.getWidth();
            mBitmapHeight = bitmap.getHeight();
            mBitmapMiddlePoint.x = (mViewWidth / 2) - (mBitmapWidth /  2);
            mBitmapMiddlePoint.y = (mViewHeight / 2) - (mBitmapHeight / 2);

            matrix.postTranslate(mBitmapMiddlePoint.x, mBitmapMiddlePoint.y);
            this.setImageMatrix(matrix);
        }
    }

    @Override
    public boolean onTouch(View v, MotionEvent event){
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
            savedMatrix.set(matrix);
            mStartPoint.set(event.getX(), event.getY());
            mode = DRAG;
            break;
        case MotionEvent.ACTION_POINTER_DOWN:
            oldDist = spacing(event);
            if(oldDist > 10f){
                savedMatrix.set(matrix);
                midPoint(mMiddlePoint, event);
                mode = ZOOM;
            }
            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_POINTER_UP:
            mode = NONE;
            break;
        case MotionEvent.ACTION_MOVE:
            if(mode == DRAG){
                drag(event);
            } else if(mode == ZOOM){
                zoom(event);
            } 
            break;
        }

        return true;
    }



   public void drag(MotionEvent event){
       matrix.getValues(matrixValues);

       float left = matrixValues[2];
       float top = matrixValues[5];
       float bottom = (top + (matrixValues[0] * mBitmapHeight)) - mViewHeight;
       float right = (left + (matrixValues[0] * mBitmapWidth)) -mViewWidth;

       float eventX = event.getX();
       float eventY = event.getY();
       float spacingX = eventX - mStartPoint.x;
       float spacingY = eventY - mStartPoint.y;
       float newPositionLeft = (left  < 0 ? spacingX : spacingX * -1) + left;
       float newPositionRight = (spacingX) + right;
       float newPositionTop = (top  < 0 ? spacingY : spacingY * -1) + top;
       float newPositionBottom = (spacingY) + bottom;
       boolean x = true;
       boolean y = true;

       if(newPositionRight < 0.0f || newPositionLeft > 0.0f){
           if(newPositionRight < 0.0f && newPositionLeft > 0.0f){
               x = false;
           } else{
               eventX = oldEventX;
               mStartPoint.x = oldStartPointX;
           }
       }
       if(newPositionBottom < 0.0f || newPositionTop > 0.0f){
           if(newPositionBottom < 0.0f && newPositionTop > 0.0f){
               y = false;
           } else{
               eventY = oldEventY;
               mStartPoint.y = oldStartPointY;
           }
       }

       if(mDraggable){
           matrix.set(savedMatrix);
           matrix.postTranslate(x? eventX - mStartPoint.x : 0, y? eventY - mStartPoint.y : 0);
           this.setImageMatrix(matrix);
           if(x)oldEventX = eventX;
           if(y)oldEventY = eventY;
           if(x)oldStartPointX = mStartPoint.x;
           if(y)oldStartPointY = mStartPoint.y;
       }

   }

   public void zoom(MotionEvent event){
       matrix.getValues(matrixValues);

       float newDist = spacing(event);
       float bitmapWidth = matrixValues[0] * mBitmapWidth;
       float bimtapHeight = matrixValues[0] * mBitmapHeight;
       boolean in = newDist > oldDist;

       if(!in && matrixValues[0] < 1){
           return;
       }
       if(bitmapWidth > mViewWidth || bimtapHeight > mViewHeight){
           mDraggable = true;
       } else{
           mDraggable = false;
       }

       float midX = (mViewWidth / 2);
       float midY = (mViewHeight / 2);

       matrix.set(savedMatrix);
       scale = newDist / oldDist;
       matrix.postScale(scale, scale, bitmapWidth > mViewWidth ? mMiddlePoint.x : midX, bimtapHeight > mViewHeight ? mMiddlePoint.y : midY); 

       this.setImageMatrix(matrix);


   }





    /** Determine the space between the first two fingers */
    private float spacing(MotionEvent event) {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);

        return (float)Math.sqrt(x * x + y * y);
    }

    /** Calculate the mid point of the first two fingers */
    private void midPoint(PointF point, MotionEvent event) {
        float x = event.getX(0) + event.getX(1);
        float y = event.getY(0) + event.getY(1);
        point.set(x / 2, y / 2);
    }


}

This is how you can use it in your activity:

CustomImageVIew mImageView = (CustomImageVIew)findViewById(R.id.customImageVIew1);
mImage.setBitmap(your bitmap);

And layout:

<your.package.name.CustomImageVIew
        android:id="@+id/customImageVIew1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_marginBottom="15dp"
        android:layout_marginLeft="15dp"
        android:layout_marginRight="15dp"
        android:layout_marginTop="15dp"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true" 
        android:scaleType="matrix"/> // important

Answer 2

Method to call the About&support dialog

 public void setupAboutSupport() {

    try {

        // The About&Support AlertDialog is active
        activeAboutSupport=true;

        View messageView;
        int orientation=this.getResources().getConfiguration().orientation;

        // Inflate the about message contents
        messageView = getLayoutInflater().inflate(R.layout.about_support, null, false);

        ContextThemeWrapper ctw = new ContextThemeWrapper(this, R.style.MyCustomTheme_AlertDialog1);
        AlertDialog.Builder builder = new AlertDialog.Builder(ctw);
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setTitle(R.string.action_aboutSupport);
        builder.setView(messageView);

        TouchImageView imgDisplay = (TouchImageView) messageView.findViewById(R.id.action_infolinks_about_support);
        imgDisplay.setMaxZoom(3f);

        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.myinfolinks_about_support);

        int imageWidth = bitmap.getWidth();
        int imageHeight = bitmap.getHeight();
        int newWidth;

        // Calculate the new About_Support image width
        if(orientation==Configuration.ORIENTATION_PORTRAIT ) {
            // For 7" up to 10" tablets
            //if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
            if (SingletonMyInfoLinks.isTablet) {
                    // newWidth = widthScreen - (two borders of about_support layout and 20% of width Screen)
                newWidth = widthScreen - ((2 * toPixels(8)) + (int)(widthScreen*0.2));
            } else newWidth = widthScreen - ((2 * toPixels(8)) + (int)(widthScreen*0.1));

        } else {
            // For 7" up to 10" tablets
            //if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
            if (SingletonMyInfoLinks.isTablet) {
                newWidth = widthScreen - ((2 * toPixels(8)) + (int)(widthScreen*0.5));

            } else newWidth = widthScreen - ((2 * toPixels(8)) + (int)(widthScreen*0.3));
        }

        // Get the scale factor
        float scaleFactor = (float)newWidth/(float)imageWidth;
        // Calculate the new About_Support image height
        int newHeight = (int)(imageHeight * scaleFactor);
        // Set the new bitmap corresponding the adjusted About_Support image
        bitmap = Bitmap.createScaledBitmap(bitmap, newWidth, newHeight, true);

        // Rescale the image
        imgDisplay.setImageBitmap(bitmap);

        dialogAboutSupport = builder.show();

        TextView textViewVersion = (TextView) dialogAboutSupport.findViewById(R.id.action_strVersion);
        textViewVersion.setText(Html.fromHtml(getString(R.string.aboutSupport_text1)+" <b>"+versionName+"</b>"));

        TextView textViewDeveloperName = (TextView) dialogAboutSupport.findViewById(R.id.action_strDeveloperName);
        textViewDeveloperName.setText(Html.fromHtml(getString(R.string.aboutSupport_text2)+" <b>"+SingletonMyInfoLinks.developerName+"</b>"));

        TextView textViewSupportEmail = (TextView) dialogAboutSupport.findViewById(R.id.action_strSupportEmail);
        textViewSupportEmail.setText(Html.fromHtml(getString(R.string.aboutSupport_text3)+" "+SingletonMyInfoLinks.developerEmail));

        TextView textViewCompanyName = (TextView) dialogAboutSupport.findViewById(R.id.action_strCompanyName);
        textViewCompanyName.setText(Html.fromHtml(getString(R.string.aboutSupport_text4)+" "+SingletonMyInfoLinks.companyName));

        Button btnOk = (Button) dialogAboutSupport.findViewById(R.id.btnOK);

        btnOk.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dialogAboutSupport.dismiss();
            }
        });

        dialogAboutSupport.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Override
            public void onDismiss(final DialogInterface dialog) {
                // the About & Support AlertDialog is closed
                activeAboutSupport=false;
            }
        });

        dialogAboutSupport.getWindow().setBackgroundDrawable(new ColorDrawable(SingletonMyInfoLinks.atualBackgroundColor));

        /* Effect that image appear slower */
        // Only the fade_in matters
        AlphaAnimation fade_out = new AlphaAnimation(1.0f, 0.0f);
        AlphaAnimation fade_in = new AlphaAnimation(0.0f, 1.0f);
        AlphaAnimation a = false ? fade_out : fade_in;

        a.setDuration(2000); // 2 sec
        a.setFillAfter(true); // Maintain the visibility at the end of animation
        // Animation start
        ImageView img = (ImageView) messageView.findViewById(R.id.action_infolinks_about_support);
        img.startAnimation(a);

    } catch (Exception e) {
        //Log.e(SingletonMyInfoLinks.appNameText +"-" +  getLocalClassName() + ": ", e.getMessage());
    }
}

Answer 3

I am Using this one it is working perfectly.

<your.packagename.MyZoomableImageViewTouch
        android:id="@+id/mediaImage"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scaleType="matrix"/>

My a MyZoomableImageViewTouch class is below:

public class MyZoomableImageViewTouch extends ImageViewTouch
{

    static final float SCROLL_DELTA_THRESHOLD = 1.0f;

    public MyZoomableImageViewTouch(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        init();
    }

    public MyZoomableImageViewTouch(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public MyZoomableImageViewTouch(Context context)
    {
        super(context);
        init();
    }

    private void init() {
        View.OnTouchListener listener = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                if (getScale() > 1f) {
                    getParent().requestDisallowInterceptTouchEvent(true);
                } else {
                    getParent().requestDisallowInterceptTouchEvent(false);
                }
                return false;
            }
        };
        setOnTouchListener(listener);
        setDisplayType(DisplayType.FIT_TO_SCREEN);
    }

    @Override
    protected float onDoubleTapPost(float scale, float maxZoom) {
        if (scale != 1f) {
            mDoubleTapDirection = 1;
            return 1f;
        }
        if (mDoubleTapDirection == 1) {
            mDoubleTapDirection = -1;
            if ((scale + (mScaleFactor * 2)) <= maxZoom) {
                return scale + mScaleFactor;
            } else {
                mDoubleTapDirection = -1;
                return maxZoom;
            }
        } else {
            mDoubleTapDirection = 1;
            return 1f;
        }
    }

    @Override
    public boolean canScroll(int direction) {
        RectF bitmapRect = getBitmapRect();
        updateRect(bitmapRect, mScrollRect);
        Rect imageViewRect = new Rect();
        getGlobalVisibleRect(imageViewRect);

        if (null == bitmapRect) {
            return false;
        }

        if (Math.abs(bitmapRect.right - imageViewRect.right) < SCROLL_DELTA_THRESHOLD) {
            if (direction < 0) {
                return false;
            }
        }

        if (Math.abs(bitmapRect.left - mScrollRect.left) < SCROLL_DELTA_THRESHOLD) {
            if (direction > 0) {
                return false;
            }
        }
        return true;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
    {
        if (getScale() == 1f) return false;
        if (distanceX != 0 && !canScroll((int) -distanceX)) {
            getParent().requestDisallowInterceptTouchEvent(false);
            return false;
        } else {
            getParent().requestDisallowInterceptTouchEvent(true);
            mUserScaled = true;
            scrollBy(-distanceX, -distanceY);
            invalidate();
            return true;
        }
    }
}